Abstract: Dietary ﬁber improves host insulin sensitivity and obesity through the eﬀects of short chain fatty acids (SCFAs) such as acetate，propionate，and n-butyrate，produced by gut microbial fermentation. SCFAs not only serve as energy sources for the host，but also play an essential role as signaling molecules in host energy homeostasis-related physiological functions via the G protein-coupled receptors; GPR41，GPR43，or Olfr78. Our recent study indicates that barley β-glucan consumed as dietary fiber causes appetite suppression and ameliorates insulin sensitivity via SCFA-induced production of gut hormones. Moreover，we previously reported that SCFAs play an important role in the regulation of energy homeostasis via their SCFA receptors that are present in host tissues. Specifically，GPR41 mediates sympathetic activity and GPR43 is primarily involved in the adipose-insulin signaling. In addition，recent evidence suggests that dietary ﬁber and the gut microbial-derived SCFAs exert multiple beneﬁcial eﬀects such as immune regulation via epigenetic regulation of gene expression by inhibiting histone deacetylase. In this review，we summarize the roles of gut microbial SCFAs in the host energy regulation and present an overview of the current understanding of its physiological functions. These ﬁndings would provide a new insight into the interaction between gut microbes and the host.